Harington has now revealed that he has never asked Martin about the identity of Jon Snow's mother.

"I've tried to trick [showrunners] David [Benioff] and Dan [Weiss] into telling me," he joked to Vulture.

He went on to speculate about his character's future: "I genuinely don't want to know, whoever it is. One reason I don't think he dies is that he hasn't found out who his mother is.

"I don't want to predict this, because George could just kill him, but I just think Jon's got to find out who his mother is. He's got to. It would be unfair if he didn't.

"And he doesn't think he ever will. But we just need to see him find out. That's my feeling, anyway."

Harington added that he enjoys learning more about Jon Snow as each season progresses.

"It's fascinating what George has done, and how people love to speculate," he added. "And only he knows. Whatever he knows, I'm sure he's masterminded it in his head and he knows how it's going to end.